Electric switch



Oct. 13, 1942. Q A, SCHAEFER 2,299,038

ELECTRIC SWITCH Fled"Feb. 20, 1939 4 Sheets-Sheet l 5 [N VENTOR fr! 17. Sca-efe/ A TTOR NE Y ELECTRIC SWITCH 7 Wwf/,M

' ATTORNEY Ot. 13, 1942. c. A. scHAEl-ER 2,299,033.

mncmc swITcH Filed Feb. 29, 1959 4 sheets-sheet s /NI/ENTOA ct. 13, 1942. c, A, SCHAEFER 2,299,038

ELECTRIC SWITCH -Filel Feb. `20, 1939 4 Sheets-Sheet 4 /NVE/VTOR Patented Oct. 13, 1942 ELECTRIC SWITCH can A. Schaefer, permit, Mich., assignor to Detroit, Mich., a corpora- Square D Company, tion of Michigan Application February 20, 1939, Serial No. 257,285

(Cl. 20D-'83) 14 Claims.

'I'his invention relates to devices for making and breaking electrical circuits and more particularly to electric switches automatically operable in response to variations in external conditions.

One object of this invention is to provide an improved mechanism for securing quick make and break of the contacts of an automatically operating electric switch responsive to applied pressure or other external condition.

Another object of the invention is to provide an automatically operating electric switch normally operative in response toA variations in external conditions with an improved form of manual contact operating means affording quick make and break of the switching contacts.

Another object of the invention is to provide a new and improved construction of an electric switch automatically operating in response to variations in applied pressure, and an unloader valve, with operation of the valve in response to actuation of the switch.

Another object of the invention is to provide an electric switch according to the preceding object with manual means for opening the circuit through the switch and for operating the unloader valve.

Another object of the invention is to provide an improved form of current responsive overload relay for an electric switch.

Another object of the invention is to provide an improved current responsive overload relay for an electric switch, manual and automatic operation, with the automatic operation occurring independently of the Vmanual operating means.

Other objects and features of the invention will be readily apparent to those skilled in the art from the following specification and the appended drawings illustrating certain preferred embodiments of the invention in which:

Figure l is a plan view of the switch with the cover removed.

Figure 2 is a sectional view taken along line II-II of Figure 1.

Figure 3 is a sectional view taken along line III- III of Figure 1.

Figure 4 is a sectional View taken along line IV-IV of Figure 1.

Figure 5 is a plan view of a modication with the switch cover removed. l

Figure 6 is a side elevational view of the modification.

Figure 7 is a sectional view taken along line VII-VII of Figure 6.

Figure 8 is a plan view partially cut away of another modification with the switch cover removed.

Figure 9 is a sectional view taken along line IX-IX of Figure 8.

Figure 10 is a sectional view taken along line Xk-X of Figure 9.

Figure 11 is a sectional view taken along line XI-XI of Figure 10.

Figure 12 is a sectional view taken along line XII-XII of Figure 9.

This invention, as illustrated by Figures 1-4 inclusive, consists of an enclosing box I with its base 2 having an opening 3 pressed therefrom and with the inwardly directed flange 4 encircling said opening. A connecting flange 5 is attached to\ the base 2 as by threaded studs 6 and is pro-` vided with a connector I rigidly afiixed thereto as by welding. The connector 1, in turn, is provided with a pulsation reducing orifice 8. Disposed between the outer surface of base 2 and the connecting flange 5 is a diaphragm 9. 'I'he connecting flange 5 is provided with a circular ridge I0 which is pressed against the diaphragm 9 by Astuds 6, forcing the diaphragm 9 tightly against the base 2 and thus providing an air tight t. The diaphragm 9 has resting upon its inner surface the pressure plate II composed of a disk I2 and a U-shaped member I3 rigidly attached thereto as by welding. The ends of the legs of the U-shaped member I3 are pointed and pass through openings in a mounting plate I5 with the points tting into seats in the base of a main operating lever I6 and acting as a pivot for the latter. The mounting plate I5 rests upon a bearing plate I'I and both are secured to the base 2 by means of studs.

The mounting plate I 5 is provided with a raised central portion I8 having an opening therein to receive a bolt I9 which is rigidly fixed to the mounting plate I5, and has a range spring 2i disposed upon it between spring seats 22 and 23. The upper portion of bolt I9 is threaded to receive a nut 24 to adjust the compression of range spring 2I and the end of the bolt passes through the box cover and serves as a means for attachment of the latter to the main assembly.

The upper surface of the mounting plate I5 provides a seat for a generally U-shaped frame 25 which is provided with flanges 26 having threaded openings therein receiving studs 21 to fix the frame to the mounting plate. The bight of the frame 25 is provided with an opening to permit the passage of bolt I9 and range spring 2l.

'Ihe operating lever I6 is pivotally attached to the frame 25 by means of a pin 28 passing through openings in the ears 30 of the operating lever I6 and into openings in opposing legs 29 and 3| of the frame. A cotter pin 20 serves to hold the pin 28 in position. The operating lever i6 is provided with seats 32 pressed therein at its opposite edges and at thev front thereof to receive the legsof U-shaped portion i3 of the pressure plate il. The operating lever |6 has two pointed bearing portions 33 pressed\out of its base and tted into depressions in the spring seat 22. lThe lever i6 is provided at its front with an opening to permit the passage of the bolt i9 and at its rear with flange 34 having a. collar 35 thereupon and with an opening therethrough. A clamp bushing 36 is fitted into the opening of collar 35 to receive the dierential adjusting screw 31 which bears upon the rear toggle spring seat 38. 4/

A toggle link 39 is disposed' intermediate the legs 29 and 3| of the frame 25 and is provided with arms 40 having at one extremity outwardly directed flanges 4| ending in knife edges. Seats 42 pressed out of legs 29 and 3| of frame 25 receive the knife edges of flanges 4| to furnish a pivot for the toggle link 39.l The opposite eX tremity of the toggle link 39 is provided with a return bent flange 44 bearing upon rear toggle spring seat 45. Disposed between the toggle spring seats 38 and 45 and the arms 48 of the toggle link 39 is the toggle spring 46 which serves to bias the toggle in position.

A generally U-shaped contact lever 41 is pivotally attached to frame 25 by pivot studs 48 passing through openings in legs 49 and 50 of the lever and rigidly secured to the legs of the frame 25. Leg 58 of the lever l1 is provided with a striker pin 5l rigidly fastened thereto at its front edge which is acted upon by the toggle arm 638 to pivot the contact lever il about the studs 88.

The contact lever i? has an insulating contact yoke 52 mounted thereon between anges 53 and 56 by a movable contact pin 55, provided with an equalizer spring 56 disposed between cup washers 5l and held in place by a clip 58. The contact yoke 52 is provided with a pair of movable contacts 59 held in position by movable contact pins 68 passing through openings in the upper corners of the yoke and carrying equalizer springs 9| held in position between cup washers 62. The contacts 59 are maintained in closed position by a contact pressure spring 63 interconnecting flange 58 of the contact lever leg t9 and an upwardly directed flange 65 on the bight of frame 25. The downward movement of the contact 'lever l1 is limited by the inwardly pressed abutment portion 96 which engages the leg 58 of the contact lever.

An insulating terminal block 61 is mounted upon the frame 25 and secured thereto by means of threaded studs 68 passing through openings in the block and threaded into the bight of frame 25. The block 61 has four terminal straps S8 of generally U-shape attached thereto and separated one from the other by ribs 10 on the block. The legs 1| of the straps 69 are secured to the block 61 as by threaded studs 12 and the opposite legs 13 are provided with stationary contacts 14 secured thereto and to the block by means of threaded studs 15. The block 61 is provided with an opening centrally thereof permitting the passage of bolt i9 and range spring 2|.

Automatic operation of the switch is obtained by the action of pressure operating through the pulsation reducing orifice 8 and upon the diaphragm 9. The diaphragm then forces the pressure disk upward so that the legs of the U- shaped member i3 will carry the operating lever seats 32 upwardly causing the operating lever I6 to move about the pin 28 in a counter-clockwise direction, against the opposition of the force exerted by the range compression spring 2|. As the operating lever i6 is moved upward past the center line of toggle spring 46, the toggle link 39 will be snapped Aquickly downward pivoting about its knife edges in seats 42 of the frame 25 in a counter-clockwise direction and the arm 40 of the toggle link will engage striker pin 5| attached to contact lever leg 50, moving it downwardly and consequently effecting a clockwise rotation of the contact lever 41 about the pivot studs 48 to open the circuits through the switch. Upon decrease in pressure to a predetermined value, the operating lever I6 is moved in reverse direction to snap the toggle link 39 in clockwise direction to release the contact lever 41 which moves counter-clockwise to close the vcircuit under the influence of its biasing spring 63.

Manual operating of the switch is obtained through the use of a side operating handle 16 connected to a shaft 11 passing through an opening in the wall of box and supported in a horizontal position by means of a bracket 18 provided with an opening to receive the shaft. Integrally attached to shaft 11 is an arm 19 having an outwardly directed flange 88 connected by spring 8| with a ange 82 on an arm 83 which is pivotally attached to the shaft 11 by means of a swivel bushing 84. The arm 83 is provided with an abutment 85 passing through a slot in the leg 29 of frame 25 to engage the underside of contact lever leg 58. When the contacts 59 are in closed position, the abutment rests at a sufficient distance below the contact lever leg 58 that it does not interfere with the automatic operation of the switch. To break contact, the operating handle 16 is turned counter-clockwise, rotating the shaft il and the arm 'E9 in a like direction, placing the spring 8| in tension. As the arm 'i9 passes through the line of force of the spring 8|, it is snapped quickly through dead center, and the force exerted by the spring acts upon ange 89 to cause arm 89 to move with a snap motion in a clockwise direction to engage the contact lever leg 58 and pivot contact lever l1 in a clockwise direction, thereby providing a quick make and break for the contacts.

lin the modification illustrated in Figures 5 7 inclusive, the switch includes a valve 86 provided with an inlet port 81 and an outlet port 88. The valve has an opening 89 of a constant width generally centrally thereof, extending to valve seat 98 where it joins the narrower passage 9i extending upwardly from the base of the valve. Within the opening 89 is disposed a valve pin 92 provided with an opening 93 centrally therein terminating in seat 98 upon which spring 95 bears to force pin 92 into valve seat 90; the opposite end of the spring i3 received within an opening in the under surface of studs 96 threaded into the top of the valve. A shaft 91 is disposed in the passage 9| with its upper end located directly below valve pin 92 and adapted to engage said valve pin 92 to unseat it. The upper portion of the shaft 91 is of a diameter smaller than the passage 9| to permit leakage from the valve through the outlet port 88 into the atmosphere when the shaft unseats the valve pin. The shaft 91 rests upon a lever arm 98 pivotally secured to the valve body exterior. A lever is rigidly secured to the toggle link 39 and extends through an opening in the box to the exterior thereof. The lever arm 98 is provided with an abutment portion 99 which rests upon the lever |00. When the switch is operated to open the contacts in response to theapplied pressure, actuation of the toggle link 39 in a. clockwise direction carries with it the lever |00. The abutment piece 99 resting upon lever |00 is moved upwardly to force the shaft 91 up against the valve seat 90 and unseating it to thereby open the valve.

- The operating handle 16 is provided with a pin |0| adapted to strike an inwardly directed abutment portion |02 of the lever arm 98 so that when the operating handle I is manually directed in a clockwise direction, the arm 98 is pivoted in a counter-clockwise direction to impel shaft 91 upwardly against valve pin 92 forcing it off' the valve seat 90 and opening the valve.

The modification illustrated in Figures 8-12 inclusive is provided with an overload relay |03 consisting of a frame |04 fitted into the terminal block 98 and having an opening in the top of the frame for the passage of an operating member |05. A push button |06 is mounted on the end of the operating member and has a clearance opening in its base to prevent interference with the protruding extremity of latch |0 in case the push button is held down while the relay operates in response to overload. The lower extremity of the operating member |05 is provided with an outwardly directed piece |01 connected to the top of the frame |04 by a spring |60 to bias the push button |06 upwardly. The operating member |05 is provided with an inclined abutment piece |08 bearing against the underside of a flange |09 on the latch ||0 to retain the operating member |05 within the frame against the upward pull of spring |60. 'I'he latch member |0 is positionedrrwithin the frame |04 at generally right angles to the operating member |05 and is provided with a flange connected to the top of the frame by a spring ||2. The latch member ||0 has at its lower extremity a slotted opening ||3 receiving a pin ||4 which is rigidly fixed in opposite sides of the terminal block 98 and serves to limit the upward and downward movement of thel member |0.

The operating member 05 is provided with an elongated element ||5 pivotally mounted thereon and adapted to slide against a stationary guide ||6 extending downwardly from the top of frame |04. The element ||5 has a hook ilange ||1 provided at its upper extremity to engage an abutment portion ||9` on the latch member I0. Therefore, manually forcing the operating member |05 downwardly will move element I5 in like direction and, from the engagement of hook ||1 with the abutment H9, the latch member |0 will be carried downward until abutment ||9 provided upon latch member ||0 engages the teeth of a gear wheel |20 of a solder pot relay secured to downwardly directed ange |2| of the frame |04.

Element ||5 is moved pivotally at the lower extreme of its movement by engagement of a cam surface at its lower end with a. set screw |30, secured to the side of the frame |04. This movement unlatches hook ||1 from abutment ||8 to prevent holding of latch ||0 inwardly by the push button if an overload should occur. The guide piece ||6 rotates element ||5 back into latching position as the operating member |05 is moved upwardly.

The relay |03 is provided with a pusher |23 which is adapted to extend through an opening |24 in the terminal block 61 to hold the movable contacts 6| free of the stationary contacts .14. The pusher |23 is pivotally attached by a pin |25 to arm |26 which is in turn pivotally attached to a stationary flange |21. The pin |25 is enlarged at one end, and rests upon an abutment surface |28 provided on latch member'l I0. Thus the positions assumed by the pusher |23, the pin |25, and the arm 26, are all dependent upon the position of the abutment surface |28. Therefore, when the latch member ||0 is forced downward, it carries the abutment surface |28 in the same direction and this is followed by pin |25 to retract pusher 23 and to place contact movement under the control of the normal operating mechanism.

The member |0 may be forceably disengaged from the gear by pulling the push button |06 upwardly causing the inclined abutment piece |08 to engage the underside of flange |09 and force the latch member |0 outwardly away from the gear |20 thereby freeing abutment ||9 from the gear teeth whereupon the spring ||2 will carry the latch member I0 upwardly until stopped by pin ||4.

I'he solder pot relay itself is of conventional construction and includes a solder pot |29 in which is a fusible metal secured shaft upon which the gear wheel |20 is mounted A serially connected heater coil |30 is wound about the solder pot to heat it in response to current flowing therethrough. Upon the occurrence of an overload current, the metal within the pot fuses allowing the gear wheel 20 'to rotate and to release latch member ||0; the consequent upward movement of the latter under the action of spring ||2 carries the abutment surface |20 in like direction and carrying the pin |25, the arm |26, andthe pusher |23 with it, thus forcing the pusher through opening |24 against the contacts and consequently breaking the circuit. To reset the overload relay to permit the contacts to engage under the operation of the normal mechanism, the push button is pushed inwardly as previously described.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

What is claimed is:

1. vIn an electric switch, stationary and movable contacts, means including a toggle link and a main operating lever for actuating said movable contact to make and break the circuit, spaced pivotal mountings for said link and said lever with the ends of said link and said lever directed toward each others point of mounting, an angular extension on said main operating lever, an adjusting means carried upon said angular extension, a return bent portion upon said link, a toggle spring disposed between and held in compression by said return bent toggle link portion and said adjusting means and movable through its dead center position during movement of the main operating lever to extreme positions, said spring being adjustable through said adjusting means to vary the differential of operation of the switch.

2. In an electric switch, stationary and movable contacts, means including a toggle link and a main operating lever for actuating said movable contact to make and break the circuit, spaced pivotal mountings for said link and said lever with the ends of said link and said lever directed toward each others point of mounting, an angular extension on said operating lever disposed between the pivotal mountings of the toggle link, an adjusting means carried by said angular extension, a return bent portion upon said link, spaced leg portions upon said link, a toggle spring disposed between and held in compression by said return bent portion and said adjusting means and rmovable between the legs of the toggle link to pass through its dead center position during movement of the main operating lever to extreme positions, said spring being adjustable through said adjusting means to vary the differential of operation of the switch.

3. In a pressure switch, stationary and movable contacts, means normally biasing said contacts into engaged position, a switching member mova-ble to move said movable contact to engaged and disengaged positions, an abutment portion on said switching member, toggle means having a portion thereof disposed above said abutment portion and engageable therewith to move said switching member to disengaged position with a snap action; means responsive to a pressure condition to actuate said toggle means, an extended portion on a leg of said switching member, an

overcenter spring means including a pivotal member for engaging the underside of said extended portion, and manual means for actuating said overcenter spring means to move the switching member with a snap iaction and e'ect a like movement of the movable contact to disengaged position without moving said toggle means,

4. In a pressure switch, stationary and movable contacts, a switching member movable to move said movable contact to engaged and disengaged positions, an unloader valve, means including a toggle means to move said switching member to on and oi positions with a snap action, means responsive to a pressure condition to actuate both said toggle means and said unloader valve, manual means carrying an overcenter spring means thereon, said overcenter spring means including a pivotal member engageable with the switching member to move said switching member to the off position with a snap action independently of the toggle means actuated by the pressure responsive means.

5. In a pressure switch, stationary and movable contacts, a switching member movable to move said movable contact to engaged and disengaged positions, an unloader valve, means responsive to a pressure condition to actuate both the switching member and the unloader valve, manual means to actuate the unloader valve independently of the pressure responsive means, an overcenter spring means operable by said manual means, said overcenter spring means being engageable with the switching member to move said switching member independently of the pressure actuated means to the off position with a snap action when said manual means is actuated.

6. In a pressure switch, stationary and movable contacts, a. switching member movable to move said movable contact to engaged and disengaged positions, an unloader valve an abutment portion on said switching member, toggle means havmeans to the oir position with a snap action andl the unloader valve to open position.

'7. In an electric switch, stationary and movable contacts, a switching member movable to move said movable contact into engaged and disengaged positions, means automatically operable in response to an external condition to actuate said switching member, overload means also operable to actuate said switching member, said overload means including means movable in response to a current overload, toggle means operable thereby to eiect movement of the switching member, resetting means comprising a pivotal member for restoring said movable means to itsA normal position and manual means actuable to release the movable means independent of an overload to operate the toggle means to eiect movement of the switching member to break the circuit.

8. In an electric switch, a switching element, means automatically operable in response to an external condition to actuate said switching element, overload means also operable to actuate said switching element, said overload means including means movable in response to a, current overload, toggle means operable thereby to effect movement of the switching element, manual means actuable to release the movable means to operate, the toggle means to effect movement of the switching element to break the circuit and resetting means comprising a pivotal member also operable by said manual means to restore said current responsive means to operative position, said resetting means being ineffective to prevent movement of said movable means upon the occurrence of an overload even though the resetting means should be forcibly restrained from moving.

9. In an electric switch, a switching element operable in response to an external condition to make and break an electric circuit, overload means also operable to break said electric circuit, said overload means comprising a member movable in response to a current overload, resetting means for said member, means disconnecting said resetting means from the current responsive member when the latter is in its engaged position to thereby permit movement of the current responsive member independently of the resetting means, a pivotal member to move the switch element to break the circuit, means supporting said pivotal member, an abutment portion engageable by the current responsive member to cause the pivotal member to rotate to circuit breaking position, and manual means carried b-y the overload means and operable to break the electric circuit independently of the external condition.

10. In an electric switch, a switching element, means automatically operable in response to an external condition to move said switching element, overload means also operable to move said switching element, said overload means comprising a spring actuated member, current responsive latching means for said member, toggle means operable by movement of said member when released by the latching means to effect vmovement of the switching element, a manually operable resettingelement, pivotal means connecting said resetting element to said member for movement to latched position and means for releasing said pivotal connecting means when the member is relatched by said latching means so that operation of said member cannot be prevented by the forcible restraining of said resetting element, and means for manually releasing said member from said latching means when said resetting element is moved in a direction reverse to its resetting movement.`

11. In an electric switch, a Amovable contact, means automatically operable in response to an external condition for moving said contact,V an insulation block, a conductor strap disposed in a groove along the bottom of the block and entirely -below the planes of the surface thereof, a flanged vportion secured to a side of said block and serving as a conductor terminal connector, and a second anged portion secured to the opposite side of said block and having a contact thereon adapted to be engaged by said movable contact. l

12. In an electric switch, a movable contact, means automatically operable in response to an external condition for moving said contact, an insulation block, a conductor strap disposed within a groove and against the bottom 'of said block and entirely below the plane of the surface thereof, means securing one end of said conductor strap to the side of the block with said means serving as a conductor terminal connector, means securing the other end of said cnductor strap to the opposite side of the block, said last mentioned means also serving to connect a contact to said extremity.

13. In an electric switch, a movable contact, means automatically operable in response to an external condition for moving said contact, an insulation block, conductor straps disposed within a groove against the bottom of said block and entirely below the plane of the surface thereof, means securing one end of a conductor strap to the side of the block with said means serving as a conductor terminal connector, means securing the other end of said conductor strap to the opposite side of the block, said last mentioned means also serving to connect a contact to said other end, and an insulated rib disposed between each conductor terminal connector and the conductor terminal connector of the adjacent conductor strap.

14. In a pressure switch, relatively movable contacts, a switching member for effecting separation of said contacts, means for actuating said switching member and including a toggle link, a main operating lever and an overcenter spring means for interconnecting said toggle link and said operating lever, a manual member, a rst member carried by said manual member and directed at right angles therefrom, a pivotal member carried by said manual member and adapted to engage said switching member for movement thereof, overcenter spring means interconnecting said pivotal member and said first member, said manual member being actuable to move said iirst member to effect snap movement of said pivotal member to move said switching member with a snap and independently of said switching member actuating means.

CARL A. SCHAEFER. 

